Endosome regulated retinal homeostasis and disease

内体调节视网膜稳态和疾病

• 批准号: 10668691
• 负责人: CHING-HWA SUNG
• 金额: $ 53.53万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10668691
• 关键词: 3-Dimensional; Address; Affect; Agreement; Alzheimer' s Disease; Antigens; Biological Process; Cathepsins B; Clinical; Communication; Complex; Data; Disease; Disease Progression; Disease associated microglia; Early Endosome; Electron Microscopy; Electroretinography; Endosomes; Etiology; Eye; Feedback; Flow Cytometry; Functional disorder; Galectin 3; Gene Expression; Generations; Genes; Genetic; Goals; Grant; Heterogeneity; Histologic; Homeostasis; Hot Spot; Impairment; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Learning; Lesion; Link; Lipids; Lipofuscin; Lysosomal Storage Diseases; Lysosomes; Mediating; Membrane; Membrane Lipids; Messenger RNA; Methodology; Microglia; Molecular Profiling; Mus; Mutant Strains Mice; Nature; Neurons; Ophthalmoscopy; Parkinson Disease; Pathologic; Pathology; Pathway interactions; Peptide Hydrolases; Peptide Initiation Factors; Phagocytes; Phagocytosis; Phagosomes; Photoreceptors; Probability; Proteins; Resolution; Retina; Retinal Degeneration; Retinal Diseases; Retinitis Pigmentosa; Retinoids; Rhodopsin; Rod; Role; Rupture; Signal Transduction; Sphingolipids; Spielmeyer-Vogt Disease; Stimulus; Structure of retinal pigment epithelium; Synapses; Synaptic Membranes; System; Techniques; Testing; disorder subtype; effective therapy; in vivo; insight; interest; lipidomics; loss of function; migration; molecular subtypes; mouse model; nervous system disorder; neuroinflammation; novel; novel therapeutic intervention; retinal rods; tool; trafficking; transcriptome; transcriptomics; wasting

Project Summary/Abstract Loss of function and viability of rod photoreceptors is central to the etiology of retinitis pigmentosa (RP) which affects 1 in ~4,000. Our lab has a long-term interest in understanding the endosome's role in membrane trafficking of photoreceptors and much has been learned about the outer segment protein targeting. In contrast, we know very little about how the mistrafficked proteins are degraded, and the consequence(s) of the generation of non-degradable wastes. Emerging studies showed the endo-lysosomal system is a genetic hot spot for several neurological diseases such as Alzheimer's and Parkinson's, whose pathology is contributed by both the primary neuronal lesions and sustained microglial inflammation. During the past grant period, we generated a mouse line with rod-specific deletion of VPS35. The early endosomal protein VPS35 is the hub that centrally controls several interconnected trafficking pathways. VPS35 has been genetically linked to Alzheimer's and Parkinson’s. Our results showed that in these mutant mice several outer segment proteins were mislocalized and underwent proteolytic degradation. Strikingly, VPS35 deficient rod terminals accumulated massive lipid-membrane wastes, which were engulfed by the surrounding microglia, which then migrated away to the subretinal space. The latter expressed the molecular signatures of disease-associated microglia identified in Alzheimer's mouse models. The level of sphingolipid, which has been connected to synaptic membrane integrity and neural inflammation, was also abnormally elevated in mutant mice. The overarching goal here is to test a central hypothesis that the engulfment of the rod-derived sphingolipid-rich wastes activates microglia, leading to several functional deficits (e.g., phagocytosis, clearance) and inflammation. We will mechanistically investigate the pathological contribution by sphingolipids (Aim1) and microglia (Aim2) using interdisciplinary and state-of-the-art techniques (e.g., lipidomics, transcriptomes, 3D electron microscopy, multi-antigen flow cytometry) both in vivo and in vitro. We will also address whether inhibiting any of these pathways can offset the sustained microglial inflammation, and in turn, ameliorate retinal pathology. The proposed studies will provide keen insights into the fundamental understanding of the retina homeostasis harnessed by the photoreceptor-microglia crosstalk. They have a high potential to lead to new strategies for treating RP and potentially other neurological diseases with overlapping etiologies.

项目摘要/摘要 杆光感受器的功能和生存能力丧失是视网膜炎色素病病因的核心 （RP）影响1英寸约4,000英寸。我们的实验室对理解内体的角色具有长期兴趣 在膜运输光感受器和外部细分市场中已有很多了解 蛋白质靶向。相比之下，我们对刻有骨的蛋白的降解方式了解甚少， 以及不可降解废物产生的后果。新兴研究表明 内聚糖体系统是多种神经系统疾病（例如阿尔茨海默氏症）的遗传热点 和帕金森氏症的病理学由主要的神经元病变和持续性造成 小胶质细胞炎症。在过去的赠款期间，我们生成了一条带有杆特异性的鼠标线 VPS35的删除。早期内体蛋白VPS35是集中控制几个的枢纽 相互联系的贩运途径。 VPS35与阿尔茨海默氏症的基因相关， 帕金森氏症。我们的结果表明，在这些突变小鼠中，几种外部段蛋白是 错误定位并经历了蛋白水解降解。引人注目的是，VPS35缺陷杆端子 累积的大量脂质膜废物被周围的小胶质细胞吞没， 然后迁移到视网膜下空间。后来表达的分子特征 在阿尔茨海默氏症小鼠模型中鉴定出与疾病相关的小胶质细胞。鞘脂的水平 已经连接到合成膜完整性和神经炎症，也异常 在突变小鼠中升高。这里的总体目标是检验吞噬的中心假设 杆衍生的鞘脂含量富含鞘脂的废物激活了小胶质细胞，导致了几种功能性缺陷 （例如，吞噬作用，清除率）和炎症。我们将机械地研究病理 鞘脂（AIM1）和小胶质细胞（AIM2）使用跨学科和最先进的贡献 技术（例如，脂质组学，转录组，3D电子显微镜，多抗原流式细胞仪） 体内和体外。我们还将解决抑制这些途径中的任何一个是否可以抵消 持续的小胶质细胞感染，然后改善残留病理。拟议的研究将 对对视网膜体内稳态的基本理解提供了敏锐的见解 感光细胞 - 微神经蛋白酶串扰。他们具有很高的潜力，可以实现治疗RP的新策略 以及可能具有重叠病因的其他神经系统疾病。